x-circlemenu transition

/*** JS ***/

'show:transition(before)': function(){
    this.removeAttribute('hidden');
},
'hide:transition(after)': function(){
    this.setAttribute('hidden', '');
}

/*** CSS ***/

x-circlemenu[transition], x-circlemenu[transition="show"] {
  opacity: 1;
  -webkit-transform: scale(1);
  -moz-transform: scale(1);
  -o-transform: scale(1);
  transform: scale(1);
  -webkit-transition: opacity 0.3s ease, -webkit-transform ease 0.35s;
  -moz-transition: opacity 0.3s ease, -moz-transform ease 0.35s;
  -o-transition: opacity 0.3s ease, -o-transform ease 0.35s;
  transition: opacity 0.3s ease, transform ease 0.35s;
}

x-circlemenu[transition][hidden], x-circlemenu[transition="hide"] {
  opacity: 0;
  -webkit-transform: scale(0);
  -moz-transform: scale(0);
  -o-transform: scale(0);
  transform: scale(0);
}